A product line of light (135 SSU @ 100.degree. F.), intermediate (1000 SSU @ 100.degree. F.) and heavy (3000 SSU @ 100.degree. F.) hydrofinished process oils, manufactured from the corresponding distillates of naphthenic crudes, are known as Coastal Pale Oils (CPO's). These oils have many uses in industry; however, the principal end-use of a CPO is as a major ingredient in rubber process oils.
Today there is a growing demand from end-users for process oils with high solvency. In addition, there is a need for oils which are sufficiently low in aromatics content, especially polynuclear aromatics content. Simultaneously, the availability of conventional naphthenic crudes is declining. Thus, there is a need for a process which provides process oils, especially CPO's with high solvency and which process utilizes a lesser amount of naphthenic distillate.